DESPITE 'MYSTIQUE' OF CAPSULES, MANY DRUGS WORK IN OTHER FORMS

By CALVIN SIMS

Published: February 15, 1986

The recent discovery in Westchester County of Extra-Strength Tylenol capsules laced with cyanide has focused new attention on the use of capsules for drug delivery.

When capsules were invented in the mid-19th century, they provided a significant improvement in the palatability of medications. But now, experts say, their vulnerability to tampering may outweigh their benefits, especially since advances in formulating tablets have made them easier to swallow.

Many pharmaceutical companies continue to market products in capsule form, however, because the consumer has come to perceive this as the most efficient method of taking medication, according to Dr. Garnet E. Peck, director of the industrial pharmacy laboratory at Purdue. A 'Mystique' About Capsules

''There is a certain mystique that surrounds capsules among consumers.'' Dr. Peck added. ''There are times when a manufacturer will put a product in a capsule instead of a tablet to give the drug a physical appearance that is different and therefore make it more competitive.''

With acetaminophen, the active ingredient in Tylenol, there is little difference between capsules and tablets in terms of the rate at which the drug is absorbed by the body, according to Dr. Leslie Benet, chairman of the department of pharmacy at the University of California at San Francisco.

Nonetheless, a survey by the Warner-Lambert Company, the leading producer of empty gelatin capsules, in 1983 after the first Tylenol-related deaths found that 54 percent of the Americans surveyed preferred medicine in capsule form, while 29 percent preferred medicine in coated form and only 13 percent liked medicine in uncoated tablet form.

Marshall Molloy of Warner-Lambert said that after the first Tylenol poisonings, ''it was thought that the very best technology in packaging would solve the problem.'' Now, companies may well consider eliminating capsules for some over-the-counter products. Tablets Can Be Made Faster

According to Dr. Peck, it is faster and less expensive to manufacture a tablet than to produce a capsule. ''Tablets produce at about 10,000 a minute, whereas capsules are produced at around 3,000 a minute,'' he said.

The capsules have to be poured into a machine to separate the lids from the bottoms. Once separated, the capsules are filled with drugs and resealed.

''We probably could go full force with tablets,'' Dr. Peck said, ''but there are some medicines like antibiotics which do not lend themselves to the tablet form.'' He said that as tablets, these medicines would undergo chemical changes that would make them ineffective. There are other medicines, however, with potent ingredients that prevent from them being placed in capsules.

While there may be other palatable alternatives today, when capsules were invented they represented a dramatic improvement over the existing method of delivering medication. Previously, pharmacists had made pills out of a gum-like material into which the appropriate drug had been incorporated. The gum was rolled into a tube and divided into pills, which were left to harden. Many of these pills, however, never released the drugs because they would not break down in the stomach.

The first hard two-part capsule was patented in the United States in 1948. These capsules, known as cachets, were made of a thin wafer-like material and were three-quarters of an inch to an inch wide, and they dissolved very quickly once they hit the stomach.